Add a function to help debugging

src/util.c

@@ -39,6 +39,16 @@ void util_uint8_to_hex(const uint8_t* in_bin, const size_t in_len, char* out)
         rust_util_bytes(in_bin, in_len), rust_util_bytes_mut((uint8_t*)out, in_len * 2 + 1));
 }
 
+#if defined(SEMIHOSTING)
+char* util_uint8_to_hex_alloc(const uint8_t* in_bin, const size_t in_len)
+{
+    void* out = malloc(in_len * 2 + 1);
+    rust_util_uint8_to_hex(
+        rust_util_bytes(in_bin, in_len), rust_util_bytes_mut((uint8_t*)out, in_len * 2 + 1));
+    return (char*)out;
+}
+#endif
+
 void util_cleanup_str(char** str)
 {
     util_zero(*str, strlens(*str));

src/util.h

@@ -61,6 +61,10 @@ void util_zero(volatile void* dst, size_t len);
 // `out` must be of size in_len*2+1. Use BB_HEX_SIZE() to compute the size.
 void util_uint8_to_hex(const uint8_t* in_bin, size_t in_len, char* out);
 
+// This function is only compiled when we compile with SEMIHOSTING, it is convenient when debugging
+// to print byte arrays as hex.
+char* util_uint8_to_hex_alloc(const uint8_t* in_bin, size_t in_len);
+
 #define BB_HEX_SIZE(in_bin) (sizeof((in_bin)) * 2 + 1)
 
 void util_cleanup_str(char** str);